Ford harsh downshifts: 6R75 2-1, 10R60 7-6 - Transmission Digest

Ford harsh downshifts: 6R75 2-1, 10R60 7-6

Complaints, causes and corrections for two different Ford transmissions experiencing harsh downshifts.

Ford 6R75 harsh 2-1 downshift

The complaint

2007-2008 Lincoln Navigators built on or before April 17, 2008 and equipped with the 5.4-liter engine and the 6R75 transmission have a complaint of a harsh 2-1 downshift under 10 MPH as the vehicle is coming to a stop. This complaint may still be present after overhaul and will not be eliminated by clearing the Keep Alive Memory (KAM).

The cause

The Powertrain Control Module requires a software calibration update (see Figure 1, above).

The correction

Reprogram the PCM with IDS release 56.4 or higher. Since the TCM cannot be independently programmed, reprogram using the PMI function to ensure that the engine and transmission calibrations are updated to the latest level simultaneously. Verify that the TCM shows 7U74-7J104-AA as the current part number after reprogramming is complete. Note: Do not clear the KAM.

Drive the vehicle and perform the following steps while doing so to successfully complete this service procedure:

  1. Verify that the transmission fluid temperature is above 175º (80ºC).
  2. Accelerate from a stop with light throttle to 15 MPH (24 Km/h); remove your foot from the accelerator pedal.
  3. Brake very gently to a complete stop (allow at least six seconds).
  4. Repeat steps 2 and 3 five times.
  5. Accelerate from a stop with light throttle, ensuring that the 1-2, 2-3 and 3-4 shifts occur at engine speeds between 1300 and 1800 RPM.
  6. Continue to accelerate until you reach 50 MPH (80 Km/h) or the 5-6 shift.
  7. Brake gently to a complete stop and hold the foot brake for ten seconds.
  8. Repeat steps 6 and 7 three times.

The harsh 2-1 downshift will be improved at this time; however, it may take several days of driving for the transmission to fully adapt.

Ford 10R60 harsh 7-6 downshift

The complaint

Some 2020 Ford Explorers and Lincoln Aviators equipped with the 2.3 turbo engine and the 10R60 transmission, built on or before May 19, 2020, may have a complaint of a harsh 7-6 downshift. Use the Select shift mode to perform a manual 7-6 downshift; if the downshift is harsh, proceed to the correction.

The cause

The “A” clutch piston return spring retaining snap ring has become dislodged—refer to the black and white arrows in Figure 2.

Tech-Talk-January-Figure-9
Figure 2.

The correction

Replace the entire front support assembly (see Figure 3). Complete tear down is not required. It is only necessary to remove the torque converter, valve body and transmission fluid pump in order to remove the front support.

Tech-Talk-January-Figure-10
Figure 3.

Service information

10R60 Front Support Assembly: LP5Z-7A130-B

Read more articles in our Transmission Tech/Talk series here.

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